Coastal Contractor

Breakline: When a Tree Falls

When a Tree Falls

Builders take notice of the species they
plant

As a landscaping tree, the laurel oak is fast-growing, leafy, and
tolerant of poor soil — qualities that have made it a popular
choice for new homes and planned communities throughout the tree's
native range in the Southeast.

But the hurricanes of the past two decades have revealed a
downside: the laurel oak topples in high winds. Studies of downed
trees after recent Florida hurricanes have pinpointed the laurel
oak as perhaps the most common of large trees to fall. "I've
measured four hurricanes in the Pensacola area," said Mary Duryea,
urban forestry expert at the University of Florida, "and in every
one of them, laurel oaks have wreaked havoc."

Toppling trees prove to be a leading culprit in damaging houses
during high-wind events. Builders and planners seeking to make new
communities as hurricane-hardened as their houses have learned to
pay attention to the kinds of trees they plant.

Used to be, tree falls were dismissed as unpredictable and
uncontrollable. But urban foresters such as Duryea are bringing
order to the chaos. By surveying urban canopies in the aftermath of
hurricanes, they are learning how different tree species fare and
how to plant and maintain trees to maximize survivability. The
research is of interest not only to developers and planners but
also to insurers, whose billions in payouts for the 2004 storms
included millions for damage in Orlando and elsewhere inland.

Though it is not widespread, some have already called for trees to
figure more heavily into insurance considerations.

Laurel oaks (Quercus laurifolia) "are such a risk factor that I
would suggest that people's insurance should be based on the types
of trees they have," Jim Lushine, a meteorologist with the National
Weather Service in Miami, told the Lakeland Ledger last year. "I
wouldn't be opposed to even seeing some kinds of trees banned in
Florida."

By surveying urban canopies in the aftermath of
hurricanes, they are learning how different tree species
fare.

For developers and planners seeking to make new communities as
hurricane-hardened as their houses, the message is to plant
smarter. Fortunately, how-to information is becoming readily
available. Those seeking an in-depth treatment can turn to
landscape architect Pamela Crawford's 2005 book, Stormscaping:
Landscaping to Minimize Wind Damage in Florida. But a brief
discussion is also available in the just-published "Assessing
Damage and Restoring Trees After a Hurricane," from the UF
Institute for Food and Agricultural Sciences (downloadable for free
at http://edis.ifas.ufl.edu/EP291).

The publication's six authors make clear that planting smarter is
partly a matter of choosing wind-resistant species. They list
dozens of hearty candidates among palms, pines, and deciduous
trees. Duryea's research has shown that sabal palms (Sabal
palmetto), live oak (Quercus virginiana), and southern magnolia
(Magnolia grandiflora) are among the hardiest. Decay resistance is
an important factor in wind resistance: live oaks tend to resist
decay, while laurel oaks are prone to it.

How developers and community planners design tree layouts is also
important, the authors note. They write that the most important and
often overlooked design element is leaving enough soil space around
the tree for its roots to grow. Trees expected to grow large should
have at least 30 feet of unpaved space around their trunks; medium
trees, at least 20 feet; small trees, at least 10 feet. Soil should
be well drained, allowing roots to dig deep. "To provide anchorage
for the tree," the authors write, "roots need to spread beyond the
edge of the canopy and grow deep in the soil."

The authors also suggest that landscapers and developers group
trees together in larger spaces rather than planting them singly in
small spaces. This is to take advantage of trees' natural tendency
to support each other when bowed by wind. Even with the right
species correctly planted, homeowners have to prune trees carefully
to make sure they continue to be wind resistant, the authors
note.

In a paper on tree damage following Hurricanes Erin and Opal in
1995, Duryea notes that the hurricane aftermath can leave
neighborhood residents opposed to trees because of the damage they
can cause. Yet trees have many benefits, such as shade, which helps
homeowners conserve energy, Duryea writes. The implication is, the
value of urban forests trumps their risks, especially when trees
are planted and maintained to ride out hurricanes intact. —
Aaron Hoover

Currents

The 24-hour Difference

The National Oceanic & Atmospheric Administration opened a new
research institute to focus on improving hurricane forecasts. Dr.
David Shaw, director of the new Northern Gulf Institute at Stennis
Space Center, said that simply improving the ability to accurately
predict the strength and position of a hurricane at landfall within
96 hours, up from 72 hours, would drastically improve evacuations,
saving lives as well as the frustration incurred by unnecessary
evacuations.

Increased Threat

Researchers remain divided over the question of whether global
climate change is increasing tropical storm frequency and
intensity. But one thing not disputed is the increase in the
destruction. Philip J. Klotzbach, a hurricane researcher at
Colorado State University who disputes the link between global
warming and stronger storms, told The New York Times: "There is
likely to be an increase in destructiveness from tropical cyclones
regardless of whether they are getting more intense or not. This is
largely due to the increase in coastal population and wealth per
capita in hurricane-prone areas."

Premium Prices

Insurance woes a driving force for building
better houses

In the aftermath of eight hurricanes and $36 billion in insured
losses in 2004 and 2005, home and business owners are facing
insurance premium increases as high as 194%. And they are demanding
relief, driving insurance reform to the top of the list of hot
issues in Florida.

A special committee appointed by former Gov. Jeb Bush made 50
recommendations in November aimed at lowering rates and reducing
risks to insurers. During recent elections, GOP gubernatorial
candidate Charlie Crist and Democrat Jim Davis sparred over who
offered the best package of reform ideas. And the Florida
legislature planned to meet in a special session in mid-January to
tackle the issue. But it was far from clear that all the political
activity would ever amount to significantly lower rates for
Florida's over 4.4 million homeowners anytime soon.

"What is it that they can do that is going to cut premiums?" asked
Gary Landry, vice president of the Florida Insurance Council. "We
have to have adequate premiums."

Unfortunately, there is no single patch for the gaping hole of
trillions of dollars of exposed coastal property. That was made
abundantly clear by the governor's Property and Casualty Insurance
Reform Committee's recommendations, which spanned ten areas ranging
from reinsurance to building codes to market incentives. Lawmakers
were widely expected to ease the rules for insurers to buy
reinsurance from Florida's hurricane catastrophe fund, with
insurers presumably passing along savings to consumers. But that
was viewed as a short-term solution done in the hope that private
reinsurance rates will come down.

Although it would not lower premiums universally, the idea that
seemed to gain the most traction with both lawmakers and insurers
was increasing incentives for homeowners to make their homes more
hurricane worthy.

"Probably the best thing in the reform committee package," Landry
said, "is the mitigation efforts."

Mitigation techniques such as elevating a home, building shear
walls, and installing tie-down hardware will count most when the
next big storm comes.

Mitigation Minded

As longtime director of the Federal Alliance for Safe Homes, a
Tallahassee-based disaster safety organization, Leslie
Chapman-Henderson can recall a time when people brushed aside
mitigation — the measures aimed at strengthening homes to
prevent damages.

Today, she says, both Florida residents and politicians
increasingly view hardening homes against hurricanes as central to
storm preparedness.

As evidence, she cites the overwhelming response to a new state
program offering free home inspections for hurricane worthiness and
matching dollars for retrofits. Florida launched My Safe Florida
Home in August; 58,000 people had applied by November. To meet the
demand, state lawmakers were expected to expand the program this
year.

A couple of changes have pushed mitigation to the forefront.

One, the four 2004 hurricanes gave many Floridians a firsthand view
of how homes built to withstand hurricanes compare to those that
don't. Visible evidence in many neighborhoods was supported by
research showing homes built after the 2002 Florida Building Code
fared far better than earlier homes built under less stringent
codes.

Two, in response to miles-long traffic jams in the 2004 and 2005
evacuations, Florida's emergency managers have switched from
advocating widespread evacuations to urging residents in all but
the riskiest locations to stay in place. The result is, mitigating
homes is increasingly viewed as a way not only to protect property
but also to safeguard people.

"I've been around this movement for a long time, and the notion of
sheltering people in place is taking on an increased level of
importance," Chapman-Henderson says.

"It's a sea change, really, in attitudes."

How mitigation will affect homeowner's insurance premiums remains
to be seen. A new law will require Florida's insurance companies to
disclose by March 1 exactly how much policyholders can reduce
premiums through steps such as opening protection for windows and
doors. But the numbers will differ based on the company, the
location, and type of home. The biggest discounts will probably be
available to homeowners in southeast Florida, still considered the
state's highest risk area, who potentially cut their rates by as
much as 50%, Chapman-Henderson said. — A.H.